| Abstract Scope |
Aluminum alloys 4943 (Al-5.5wt%Si-0.4wt%Mg), 4043 (Al-5.5wt%Si), and 4047 (Al-11.6wt%Si) are commonly used in wire arc additive manufacturing (WAAM) for their resistance to corrosion and ease of welding. Because alloy 4943 exhibits the highest as-welded strength, it is relevant for WAAM of large-scale, complex, aluminum parts. Near net shape 3D-printing of aluminum parts followed by machining provides an economical alternative to casting for low volume production. In this research parameters were identified for gas metal arc welding (GMAW) of aluminum alloy 4943 using a KUKA KR 50 R2500 robotic arm coupled with a two-axis positioner. The 4943 wire was deposited using the Fronius cold metal transfer (CMT) process. A Fronius CMT Advanced welding power supply was used and the synergic line CMT1368 Adv (v1.2.0) was chosen to obtain a consistent weld pattern with acceptable bead fusion. Additionally, adjustments of the CMT mode, wire feed rate, current, torch speed, and weave pattern were applied to obtain quality layering of continuous linear beads. A custom slicer and path planning script created in Rhinoceros7 were applied to enable convenient bead pattern modification. Repositioning of strike and crater location, as well as alternating weld direction between layers, were implemented to increase dimensional accuracy. Once the paths were created, they were simulated using the offline robotic programming software Octopuz. After simulation, the path planning code was exported in the KUKA Robot Language (KRL). |